The automated factory of the future, in order to provide flexible manufacturing of various types of parts, will require versatile robotic type machines for inspecting the parts and for producing feedback correction signals to the machines as well for insuring that defective products are not released. In order to provide such inspection, various programmable coordinate measuring machines have been proposed using contact feelers and the like.
The weak links of virtually all of the approaches heretofore are generally two. First, these approaches are only capable of providing dimensional measurements and cannot inspect for the other aspects of the part, such as defective surface finish. Second, these approaches are also slow because of the time required for the sensor probe to make contact. It will be appreciated that there are definite limits on the maximum speed at which a measurement can be made when it is necessary to stop and touch a part in order to make the measurement. This is particularly true when accuracies that approach values as small as 2 or 3 microns are desired as in most inspections of a finished machined part.
A general solution to the problems discussed in the previous paragraph involves the use of an inspection robot based on optical sensing principles. One example of a robot control system of this type is that disclosed in my copending application Ser. No. 262,492, filed on May 11, 1981 and entitled "Electro-Optical Systems for Control of Robot Manipulator Arms and Co-ordinate Measuring Machines" now U.S. Pat. No. 4,453,085.